Field of the Invention
The disclosure relates to a display device, and more particularly to an organic light emitting diode touch display device that provides touch sense function.
Description of the Related Art
Referring to FIG. 1, a conventional organic light emitting diode (abbreviated as OLED hereinafter) display 1 mainly includes a substrate 10, an organic light emitting module 11 that is disposed on the substrate 10, and a transparent cover plate 12 (e.g., a glass plate or a polyethylene terephthalate (PET) plate) that covers the organic light emitting module 11. A space between peripheries of the substrate 10 and the transparent cover plate 12 would be sealed by a sealant 13 to confine the organic light emitting module 11 between the substrate 10 and the transparent cover plate 12 so as to protect the organic light emitting module 11 from absorption of moisture and oxidation. Since the OLED display 1 is self-luminous, when operated under relatively dark ambient light conditions or indoor environments, the OLED display 1 exhibits high contrast ratio and high color saturation. However, when operated under bright ambient light conditions (such as outdoor environment), since brightness of the OLED is much lower than that of external light of the environment, light reflected by a surface of the OLED display 1 would result in poor readability for a user.
Therefore, in order to solve the abovementioned problem, a conventional solution is to dispose an optical film unit (not shown) composed of a quarter-wave plate and a polarizer on the transparent cover plate 12 of the OLED display 1 to absorb the incident light from the external environment. The conventional polarizer includes a triacetate cellulose (TAC) film (as a protective layer), a polyvinyl alcohol (PVA) film (as a light polarizing body), and another TAC film (as a protective layer) that are laminated together, and has a thickness within the range from tens to hundreds of micrometers.
Moreover, to provide touch sense function to the OLED display 1, a commercially available touch sensor module (not shown) is provided on the optical film unit. However, volume and weight of the OLED display 1 with the touch sensor module would be severely increased. Therefore, it is difficult to apply to electronic devices with thin and light-weight demands.